1. Technical Field
The present invention relates to a liquid consumption apparatus that uses liquids and a liquid consumption amount control method that manages the amount of liquid consumption in the liquid consumption apparatus.
2. Related Art
There are known techniques for controlling the amount of liquid consumption in various kinds of liquid consumption apparatuses that consume liquids. An example of known liquid consumption apparatuses is a printing apparatus to which one or more ink cartridges are detachably attached so that the printing apparatus uses ink to perform a printing job processing. As an example of various techniques for managing the remaining amount of ink in such a printing apparatus, a technique for counting ink drops that are discharged from a print head is known. Another known art adopts a liquid level indication sensor for determining as to whether or not the amount of ink remaining in an ink cartridge is not more than a predetermined amount.
According to the technique that counts the number of ink drops, because it is necessary to take such factors as ink cartridge capacity error and ink drop weight variation into consideration, there has been a problem in that it is difficult to improve the utilization efficiency of ink contained in each ink cartridge. On the other hand, according to the technique that employs a liquid level indication sensor, there has been a problem in that it is impossible to control the amount of remaining ink or the amount of ink consumption until the liquid level indication sensor detects that the amount of ink remaining in an ink cartridge is not more than a predetermined amount. As an example of publication that proposes a solution for addressing the above problems, Japanese Patent No. 3,102,271 discloses a technique that adopts both of the ink-drop counting technique and the liquid level indication sensor technique, where the count value of the number of ink drops is corrected into a predetermined value upon detection of the ink amount not more than a predetermined amount by the liquid level indication sensor.
However, when the liquid level indication sensor detects that the amount of remaining ink is not more than a predetermined amount, the proposed technique, which corrects the count value of the number of ink drops into a predetermined value, could cause the second occurrence of the same count value, which could result in defective counting. That is, it is impossible to judge which count value, either the count value recognized before detection of ink amount not more than a predetermined one by the liquid level indication sensor or the count value recognized after detection thereof, is a correct value. As described above, the related art that employs both of the ink-drop counting technique and the liquid level indication sensor technique has not solved the problem of each art and posed another problem unique to such a combination approach.